This invention relates to a book binding method and a book binding apparatus for binding a book such as a passport or a bankbook, which is subjected to mechanical reading. More particularly, it relates to a book binding method and a book binding apparatus for binding a book with a rugged construction by a line of stitches of thread so as to be effective for prevention of counterfeiting.
In a typical conventional book binding method, a plurality of leaves flatly superimposed one upon another are bound at their center by a line of stitches of thread using a stitching machine and a cover is attached thereto. Then, the stitched flatly superimposed leaves are folded in two along the line of stitches of thread to form a book. Incidentally, it is necessary for such a book as a passport or a bankbook to be correctly mechanically readable and difficult to counterfeit. A book binding method satisfying such a need is disclosed, for example, in Japanese Patent Examined Publication (KOKOKU) No. 45267/95.
According to this conventional book binding method, after the flatly superimposed leaves forming inner pages are stitched with thread using a stitching machine, an adhesive agent is applied thereto along the entire length of the line of stitches of thread so that the adhesive agent is impregnated by capillary action of the stitched thread and then, the adhesive agent is dried to enhance hardening. Thereafter, the cover is attached to the leaves in such a manner as to conceal the line of stitches of thread.
Employed as a means for applying an adhesive agent is an adhesive discharge nozzle. The adhesive discharge nozzle is placed immediately under the line of stitches of thread of the flatly superimposed leaves, which are being conveyed in their flat condition along an upward inclination, with a discharge port of an adhesive agent discharge nozzle facing the line of stitches of thread. Owing to this arrangement, with the progress of the conveyance of the flatly superimposed leaves, an adhesive agent is applied directly to the line of stitches of thread from the discharge port of the nozzle. After the adhesive agent is applied, the stitched flatly superimposed leaves are transferred to a drying station where the adhesive agent is enhanced by hardening.
The book thus obtained is effective for prevention of counterfeiting because the leaves are bound or stitched by a line of stitches of thread impregnated with an adhesive agent. Moreover, the book thus obtained can be correctly mechanically be read because the adhesive agent is applied to the line of stitches of thread forming a part of the spine of the book and no raised portion is formed on the line of stitches of thread on the opening/closing side of the pages.
However, the above conventional book binding method has a drawback that considerable time is required for drying the adhesive impregnated in the thread and therefore, productivity is significantly decreased.
It has another drawback in that the adhesive agent flooded out of the discharge port of the adhesive discharge nozzle tends to be adhered to a non-required area in the vicinity of the line of stitches of thread, thus resulting in uneven coating of an adhesive agent. Particularly, when a limited amount of adhesive agent flooded out of a forward end of the adhesive agent discharge nozzle like a falling drop of water is applied directly to the line of stitches of thread while the flatly superimposed leaves are being conveyed, a proper amount of adhesive agent required in accordance with the speed of conveyance of the leaves cannot be supplied and thus the abovementioned problem for enhancing the uneven coating of adhesive agent is encountered.
The present invention has been accomplished in view of the above drawbacks inherent in the prior art.